NSA staff is researching a new method to explore potential drivers of water-quality trends using differential spatially-referenced regression in the Chesapeake Bay watershed. A new method is desired to establish direct linkages between regional patterns of observed water-quality changes and drivers. Examples include management actions, watershed properties and climatic forcing variations, within finite time scales. The resulting model can be used for predicting water-quality effects under various management scenarios in a spatially-distributed dynamic watershed system. This new methodology is expected to be published in 2018.